Genetics e2

What would lead to an increase in the amount of b-galactosidase produced by a bacterial cell?

if the lac operator is defective

a mutation that results in a mutant phenotype is termed a(n) ___ and a subsequent mutation, many gen later that restores the wild type phenotype is termed a____

forward mutation, reverse mutation (reversion)

Which of the following is incorrect concerning operons?

A) they usually contain genes involved in the same metabolic pathway

B) they are transcribed into monocistronic mRNA

C) they can be inducible and repressible

D) they are regulated by a single promotor region

E) they are common prokaryotes but rare in eukaryotes

B) they are transcribed into monocistronic mRNA

tRNAs are charged with the correct amino acid by enzymes called ____

aminoacyl-tRNA synthetases

Hydrophobic and ionic interactions among amino acids are important for determining the ____ structure of proteins

tertiary

In the initiation of trans in prokary, the ____ ribosomal subunit binds near the 5’ end of mRNA and moves along it to locate the ____ sequence

small, shine-dalgarno

Given that every cell in your body has teh same genes (genome) but cell types differe in their structure and function (proteome), which of the following has the most influence over which genes are expressed btwn different cell types?

regulatory transcription factor

When comparing chromosomes among populations of white-throated sparrows, you observe that individual from one population have a reversed gene order in the central portion of the chromosome 2 that includes the centromere. this is most likely due to ___

a pericentric inversion

What chromosomal rearrangement would be expected to have the least phenotypic effect on a vertebrate organism?

a chromosomal inversion

Eukaryotic gene expression can be repressed by ___

micro RNAs

In euk cells, translation primarily takes place in the ____

Rough ER

Which is a case of aneuplodity?

a) Paralogs (gene families) of hemoglobin genes in humans

b) polyploidy in rice

c ) a paracentric inversion on chromosome 5 in humans

d ) trisomy 18 in humans

e ) triploid carp

trisomy 18 in humans

which of the following statements about mutations is incorrect?

they can occur spont

mutagens increase the frequency of mutations

they can be passed on to offspring when they occur in somatic cells

beneficial mutations are less common than neutral oe deleterious mutations

you cannot predict where or when they occur

they can be passed on to offspring when they occur in a somatic cell

in lac operon, ___ control is exemplified by CAP- cAMP complex whereas ____ control is demonstrated by the lac repressor protein

positive, negative

the study of heritable phenotypic variation due to inherited modifications affecting gene regulation occuring without changes to the dna sequence of gene is called ___

epigenetics

regulatroy proetins such as activators and repressors have two domains that are important for their function. these two domains are ___

a dna-binding domain and a effector allosteric domain.

genomic regions containing short andem repeats (STRs) have high levels of error during replication. these replication errors are due to ____ and result in a____ in the number of times a sequence motif is repeated 

dna strand slippage ; increase

the process in which homologous chromosomes or sister chromatids fail to segregate properly during cell division, leading to an abnormal number of chromosomes is called ____

chromosome nondisjunction

a sexually reproducing species that is 2n=32 would have ___ chromosomes in a normal haploid gamete

16

after translation, chaperone proteins assist with ___

protein folding

_____ is the process in which a mRNA mol is used to synthesize a polypeptide

translation

in a ribosome, the initiator tRNA bind to the start codon AUG in the ___

peptodyl (p) site 

Stop codons differ from other codons in that they

bind to release factor instead to tRNAs

In bacteria, gene encoding proteins involve in catabolic pathways (rg lac operon) tend to be ____ whereas those involved in anabolic pathways (eg tp operon) tend to be ___

inducible ; repressible

in e.coli the presence of glucose inhibits the metabolism of lactose even if lacose is availble. the is called ___ and occurs because glucose metabolism keep level of ____ low

catabolite repression ; cAMP

which of the following might occur as a result of a mutation in a eukaryotic gene promoter region?

the rate of transcription could change

Which of the following would be likely to result in a frameshift mutation?

Deletion of 2 nucelotide bp in a n exon region

Which of the following is an example of a cis regulatory element in eukaryotes?

A

An enhancer

____ catalyzes the formation of ___ bonds between adj amino acids in a polypeptide chain

Peptidyl transferase ; peptide

The mutant allele, B, that cause sickle cell disease in humans is the reult of basepair subsition in the b-globin gene that changedthe amino acid at the 6th polypeptide from glatmic acidto valine. This mutation is an example of ____. Invidthat carrie the mutant allele have increased resistantce to )))). Which explains why the mutant alleleoccurs at significant freq in some human pops.

Missense mutation, malaria